The PUR gate trimmer and the zigzag venting slider render work more efficient

During a live demonstration at the 4th Innovation Day, we presented two patent-pending tooling innovations for polyurethane (PUR) encapsulation: a PUR gate trimmer and a zigzag venting slider. Both innovations help to improve component quality while saving time and material input. They can be used for all reaction injection molding (RIM) processes. Both innovations were invented by Bernhard Satzger, our senior project and sales manager.

Higher level of component quality, faster production and reduced material input

The newly developed gate trimmer enhances the quality of PUR components, accelerates production and reduces material input. It consists of simple mechanical components, is maintenance-free and can be fitted in almost any mold. Contrary to conventional components, the trimmer comes with a considerably shorter gate runner and a slider that closes the mold once it has been filled with PUR. This design allows polyurethane to be injected into the mold cavity in a V-shape, which ensures a particularly uniform material flow and minimizes air inclusions.  After the mold has been filled, the trimmer is activated and separates the gate from the manufactured component in the mold.  The component can then be removed from the mold without requiring any reworking.

Safe, easy-to-control process

The movement of the trimmer can be easily controlled via a connection to the machine control system. The trimmer contour is adapted to the component so as to maintain the component design.

Zigzag venting slider - designed to avoid air inclusions

With the second invention, a zigzag venting slider, BBG reliably solves the problem of unwanted air inclusions, which occurs especially during the PUR encapsulation of components with large cross-sections and complex geometries. It is integrated into the mold and can be variably adapted to the geometric design of the component at hand.  Air is guided into a chamber, the air collector, through a zigzag gap. The benefit over conventional solutions? So far, either several sliders were necessary or venting had to be provided via the mold interface.

No modifications to component design and no rework

The zigzag venting slider eliminates the need for production-related grooves and slits, which are ground into the mold for most methods used to remove air inclusions. This avoids both a change in component design and the need for time-consuming trimming work after encapsulation.

Bernhard Satzger summarizes the advantages of the PUR gate trimmer and zigzag venting slider: "Both innovations improve component quality and increase productivity because the number of rejects is reduced and rework times are eliminated.“